Snowblowers have been developed which are propelled by tractors or other vehicles and are operative to remove large quantities of snow from roadways. These snowblowers normally include a self contained power plant to drive rotating snowblower fans which discharge snow through discharge spouts at the top of the blower housing, as shown by U.S. Pat. No. 4,288,933 to Walter Fair. It will be readily appreciated that the components of these large snowblower units must be able to operate effectively in extremely adverse environmental conditions.
It has been a problem in the operation of a large snowblower which is pushed in front or rear of a prime mover to maintain the blower on a straight path, particularly when the snowblower is operating such that only one side of the snowblower is actually encountering a measurable quantity of hard packed snow (e.g., when slicing off a snow bank along the side of a roadway or to widen a previously plowed single lane roadway). In these conditions, the connected snowblower has a tendency to suck into the side bank too far. It becomes impossible to push the blower further, because the blower is out of control and past its volume capacity. The side draft becomes so intense that the prime mover is unable to force the blower head out of the snow without stopping, backing up, and repositioning the unit to take a smaller cut to lessen the cut that the prime mover and blower head can handle.